libata-link: separate out link initialization functions

Separate out link initialization into ata_link_init() and
ata_link_init_sata_spd().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 64 insertions, 20 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2be30c7a2226..3da642bd2ee2 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6061,6 +6061,68 @@ void ata_dev_init(struct ata_device *dev)
 }
 
 /**
+ *      ata_link_init - Initialize an ata_link structure
+ *      @ap: ATA port link is attached to
+ *      @link: Link structure to initialize
+ *
+ *      Initialize @link.
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep)
+ */
+static void ata_link_init(struct ata_port *ap, struct ata_link *link)
+{
+        int i;
+
+        /* clear everything except for devices */
+        memset(link, 0, offsetof(struct ata_link, device[0]));
+
+        link->ap = ap;
+        link->active_tag = ATA_TAG_POISON;
+        link->hw_sata_spd_limit = UINT_MAX;
+
+        /* can't use iterator, ap isn't initialized yet */
+        for (i = 0; i < ATA_MAX_DEVICES; i++) {
+                struct ata_device *dev = &link->device[i];
+
+                dev->link = link;
+                dev->devno = dev - link->device;
+                ata_dev_init(dev);
+        }
+}
+
+/**
+ *      sata_link_init_spd - Initialize link->sata_spd_limit
+ *      @link: Link to configure sata_spd_limit for
+ *
+ *      Initialize @link->[hw_]sata_spd_limit to the currently
+ *      configured value.
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep).
+ *
+ *      RETURNS:
+ *      0 on success, -errno on failure.
+ */
+static int sata_link_init_spd(struct ata_link *link)
+{
+        u32 scontrol, spd;
+        int rc;
+
+        rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
+        if (rc)
+                return rc;
+
+        spd = (scontrol >> 4) & 0xf;
+        if (spd)
+                link->hw_sata_spd_limit &= (1 << spd) - 1;
+
+        link->sata_spd_limit = link->hw_sata_spd_limit;
+
+        return 0;
+}
+
+/**
  *      ata_port_alloc - allocate and initialize basic ATA port resources
  *      @host: ATA host this allocated port belongs to
  *
@@ -6075,7 +6137,6 @@ void ata_dev_init(struct ata_device *dev)
 struct ata_port *ata_port_alloc(struct ata_host *host)
 {
         struct ata_port *ap;
-        unsigned int i;
 
         DPRINTK("ENTER\n");
 
@@ -6090,9 +6151,6 @@ struct ata_port *ata_port_alloc(struct ata_host *host)
         ap->ctl = ATA_DEVCTL_OBS;
         ap->host = host;
         ap->dev = host->dev;
-
-        ap->link.hw_sata_spd_limit = UINT_MAX;
-        ap->link.active_tag = ATA_TAG_POISON;
         ap->last_ctl = 0xFF;
 
 #if defined(ATA_VERBOSE_DEBUG)
@@ -6115,15 +6173,7 @@ struct ata_port *ata_port_alloc(struct ata_host *host)
 
         ap->cbl = ATA_CBL_NONE;
 
-        ap->link.ap = ap;
-
-        /* can't use iterator, ap isn't initialized yet */
-        for (i = 0; i < ATA_MAX_DEVICES; i++) {
-                struct ata_device *dev = &ap->link.device[i];
-                dev->link = &ap->link;
-                dev->devno = i;
-                ata_dev_init(dev);
-        }
+        ata_link_init(ap, &ap->link);
 
 #ifdef ATA_IRQ_TRAP
         ap->stats.unhandled_irq = 1;
@@ -6406,7 +6456,6 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
         for (i = 0; i < host->n_ports; i++) {
                 struct ata_port *ap = host->ports[i];
                 int irq_line;
-                u32 scontrol;
                 unsigned long xfer_mask;
 
                 /* set SATA cable type if still unset */
@@ -6414,12 +6463,7 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
                         ap->cbl = ATA_CBL_SATA;
 
                 /* init sata_spd_limit to the current value */
-                if (sata_scr_read(&ap->link, SCR_CONTROL, &scontrol) == 0) {
-                        int spd = (scontrol >> 4) & 0xf;
-                        if (spd)
-                                ap->link.hw_sata_spd_limit &= (1 << spd) - 1;
-                }
-                ap->link.sata_spd_limit = ap->link.hw_sata_spd_limit;
+                sata_link_init_spd(&ap->link);
 
                 /* report the secondary IRQ for second channel legacy */
                 irq_line = host->irq;